Of course, that precise code puts all the "where" definitions on the one line,
as parts of the same paragraph. What would be the best way to specify that
list, such that it appears similarly to that above source, i.e., like this?

x = y + z
where y = the value of y;
z = the value of z.

Preferably, the equals signs in the list would be aligned with the one in the
actual equation.